use proc_macro2::TokenStream;
use syn::DeriveInput;
use util::wrap_in_dummy_mod;
pub fn derive(mut item: DeriveInput) -> TokenStream {
for ty_param in item.generics.type_params_mut() {
ty_param.bounds.push(parse_quote!(QueryId));
}
let (impl_generics, ty_generics, where_clause) = item.generics.split_for_impl();
let struct_name = &item.ident;
let lifetimes = item.generics.lifetimes();
let ty_params = item
.generics
.type_params()
.map(|ty_param| &ty_param.ident)
.collect::<Vec<_>>();
let query_id_ty_params = ty_params
.iter()
.map(|ty_param| quote!(<#ty_param as QueryId>::QueryId));
let has_static_query_id = ty_params
.iter()
.map(|ty_param| quote!(<#ty_param as QueryId>::HAS_STATIC_QUERY_ID));
wrap_in_dummy_mod(quote! {
use diesel::query_builder::QueryId;
#[allow(non_camel_case_types)]
impl #impl_generics QueryId for #struct_name #ty_generics
#where_clause
{
type QueryId = #struct_name<#(#lifetimes,)* #(#query_id_ty_params,)*>;
const HAS_STATIC_QUERY_ID: bool = #(#has_static_query_id &&)* true;
}
})
}